Plastic of polyamide and epoxy resin

ABSTRACT

Process of producing plastics by reacting polyamides with epoxy resins, characterized by the fact that the diamine used to form the polyamide employed consists of 20 - 100 percent of 1-amino-3aminomethyl-3,5,5-trimethyl cyclohexane and said polyamide constitutes 10 - 99.8 percent of the mixture. The products can be shaped articles.

United States Patent Schmitt et al.

[ June 27, 1972 [541 PLASTIC OF POLYAMIDE AND EPOXY RESIN [72]Inventors: Karl Schmitt, I-Ierne; Fritz Gude, Wanne- Eickel; SiegfriedBrandt, I-Ierne, all of Germany [73] Assignee: Scholven-ChemieAktiengesellschait [22] Filed: July 3, 1968 21 App1.No.: 742,115

[30] Foreign Application Priority Data July 6, 1967 Germany ..SC1-140972 [52] US. Cl ..260/830 P, 260/78 R, 260/830 TW [51] Int. Cl ..C08g45/12 [58] Field of Search ..260/ 830 P [56] References Cited UNITEDSTATES PATENTS 3,294,759 12/1966 Gabler ..260/78 Primary Examiner-PaulLieberman Attorney-Burgess, Dinklage & Sprung [57] ABSTRACT Process ofproducing plastics by reacting polyamides with epoxy resins,characterized by the fact that the diamine used to form the polyamideemployed consists of 20 100 percent of1-amino-3-aminomethy1-3,5,5-trimethy1 cyclohexane and said polyamideconstitutes 10 99,8 percent of the mixture. The products can be shapedarticles.

9 Claims, No Drawings PLASTIC F POLYAMIDE AND EPOXY RESIN Homogeneouspolyamides of straight-chain diamines and dicarboxylic acids, ofaminocarboxylic acids and of lactams are partially crystalline. They areinsoluble in most solvents and incompatible with other polymericmaterials.

It is known that soluble polyamides can also be produced byco-condensation. They dissolve in alcohols and show even a limitedcompatibility with other polymers, and particularly with epoxy resins.Accordingly it is possible to react the polyamides with these resins atelevated temperature and produce new plastics having improvedproperties.

In order to obtain hard plastics of dimensional stability within a shortperiod of time which are of interest from an industrial standpoint, fromthe mixture of the two components, it is necessary to add epoxy resinhardeners, for instance dicyan-diarnide.

If the reaction of these copolyarnides with epoxy resins is broughtabout with hardening agents at elevated temperature, crosslinking at theamide groups takes place (J. Appl. Polym. Sci. 8, 1287 95, 1964), themixture becoming insoluble. The extent of the crosslinking is, however,slight. The said resin combinations have therefore become known only asadhesives.

Up to now it was, however, not possible to react the known copolyamideswith epoxy resins even at lower temperature, or to obtain productsusable for shaped articles in this reaction.

It has been found that polyamides whose amine component consists inwhole or in part of the mixture of stereo isomers ofl-amino-3-amino-methyl-3,5,5trimethylcyclohexane (known under the nameof isophorodiamine", in the following referred to as IPD and disclosedin U.S. Pat. No. 3,352,913) start to react even at nonnal temperaturewith epoxy compounds which contain more than one epoxy group permolecule. The reaction products immediately crosslink with each other sothat the mixtures still remain fusible and soluble and can still beworked. In this respect they behave in the same manner as the knownmixtures of epoxy resins and lowmolecular polyamines which only aftersome time give highly crosslinked rigid resins. Low-molecularpolyamines, however, have a high vapor pressure and are injurious tohealth and can therefore be worked only when precautionary measures areapplied.

The polyamides of IPD used in accordance with the invention do not havethese disadvantages. Their mixtures with epoxy compounds give plasticshaving excellent technical properties. They are characterized by theirhardness and toughness. There should be particularly emphasized theirlack of color and their dimensional stability at elevated temperatureexceptionally high for polyamide-epoxide combinations. The Vicatsoftening point are, as a rule, about 2030 higher than in the case ofthe combination of the same epoxy compound with a correspondingpolyamide which has been prepared without the use of at least 20% IPD.The high surface gloss makes use for heat-resisting coatings possible.

As can be noted from the foregoing, the plastics of the inventionconsist essentially two components. Component I is a polyamide of IPDand component II is an epoxy resin. In accordance with the invention,the percentage of the components I is preferably about 75 99.8 percentif the plastics are to be only weakly crosslinked, if at all, while inthe case of the more strongly crosslinked plastics, it is preferablyabout 75 percent, so that the percentage of the components I ispreferably in all cases between 10 and 99.8 percent. The most favorableresults are obtained with an amount of IPD Polyamide of between 50 and97 percent. By the simultaneous use of aliphatic, araliphatic, aromaticor other cycloaliphatic diamines as component of the polyamide, such ashexamethylene diamine, 1,4-diarninocyclohexane, the properties can bevaried. The amount of IPD should, however, constitute at least percentof the amine in the polyamide. As dicarboxylic acids, use may be made ofaliphatic, aromatic and hydroaromatic dicarboxylic acids, such as, forinstance, adipic acid, 2,4,4-trimethyl adipic acid, decane dicarboxylicacid terephthalic acid, and cyclohex'ane-l,4-dicarboxylic acid. The

acids may also be used in the form of their esters. Aminocarboxylicacids also in the form of their lactams can also be incorporated, suchas, for instance, e-aminocaproic acid or laurolactam. The polyamides canbe polyamides as are disclosed in U.S. Pat. No. 3,352,831.

Furthermore, up to 15 percent of the diamine component of the polyamidescan be replaced by diols. There enter into consideration, for instance,ethylene glycol, propylene glycols, butylene glycols, decane diols,tridecane diols, etc., as well as branched glycols, such as, forinstance, 2,2-dimethyl butane diol, trimethyl hexamethylene glycol,etc., or diols which bear at the same time also ether oxygen, such as,for instance, triethylene glycol, dipropylene glycol, etc., as well asmixtures of all of these compounds.

One particularly advantageous embodiment of the process of the inventionproceeds from low-molecular polyamides having average molecular weightsof less than 3,000, 70 percent of whose terminal groups are aminogroups. Due to their low softening range and their good solubility, theycan be mixed even at low temperatures with the reactive resins, so thathighly reactive epoxy resins can be used.

Adducts of high elasticity are obtained by the process of the inventionwhen reacting with epoxy resins polyamides having molecular weights ofbetween 1,500 and 10,000, and in particular between 2,000 and 7,000.

The epoxy compounds which can be used as component II are sufficientlyknown. There can be used, for instance, glycidyl ethers of polyhydricphenols, such as the bisglycidyl ether of diphenylol propane and itspolymers, glycidyl esters, for instance of isophthalic acid, epoxidizedhydrocarbons, such as vinyl cyclohexene diepoxide, and glycidyl ethersof phenol formaldehyde resins. Mixtures of different epoxy compounds canalso be employed. Monoepoxy compounds may be simultaneously employed insmall quantities.

By mixing with fillers, pigments and plasticizers, the properties of theshaped bodies and coatings produced in accordance with the invention canbe varied in known manner.

The preparation of shaped bodies and coatings is effected by mixing thetwo components I and I] possibly in a solvent and thereupon shaping ormaking into a film. The reaction can be accelerated by heating to 50 200C. By the addition of epoxy-resin hardeners which activate the component11, the reaction is also accelerated.

EXAMPLES l. Forty parts by weight of a polyamide prepared from 43 partsby weight of adipic acid and 57 parts by weight of IPD were dissolved in80 parts by weight of methanol. The solution was mixed with 15 parts byweight of an epoxy resin of an epoxy value of 0.36 prepared fromdiphenylol propane and epichlorhydrin. The resin solution was formedinto a paste with 10 parts by weight of Tit), and 0.5 parts by weight ofa finely divided silica gel and applied to a carefully cleaned steelplate. After blowing with air, the film was heated for one-half hour atC. The film was pure white, hard, had a high gloss and was adherent. TheKonig pendulum hardness was 198 seconds. The same degree of hardness isreached after 6 days at 25 C.

2. Forty parts by weight of a copolyamide prepared from 36 mol% AH salt,44 mol% e-aminocaproic acid, 8.4 mol% adipic acid and l 1.6 mol% IPD arekneaded in the hot with 5.6 parts by weight of an epoxy resin of anepoxy value of 0.48 prepared from diphenylol propane and epichlorhydrin.The mixture is pressed in a plate mold and heated for one-half hour at140 C. The product is a colorless plate.

The Vicat softening point is 136 C.

3. Forty parts by weight of a copolyamide prepared from 45 mol% AH saltand 55 mol% e-aminocaproic acid are kneaded in the hot with 5.6 parts byweight of the epoxy resin used in Example 2. The mixture is pressed in aplate mold and heated for 2 hours at C. to produce a plate.

The Vicat softening point is 84 C.

4. Forty parts by weight of a polyamide of an average molecular weightof 1,020 prepared from 43 mol% adipic acid and 57 mol% of IPD arekneaded with 30 parts by weight of an epoxy resin of and epoxy value of0.36 prepared from diphenylol propane and epichlorhydrin. The mixture ispressed in a plate mold and heated for one-half hour at 140 C. toproduce a late.

l'he Vicat softening point of the colorless product is 163 C.

5. Forty parts by weight of a polyamide prepared from 57 mol% lPD, 33mol% decane dicarboxylic acid and mol% terephthalic acid are dissolvedtogether with parts by weight of the epoxy resin used in Example 2 in100 parts by weight of methanol. A plasticized PVC sheet is coated withthis solution. The colorless coating is hard and flexible and adherentafter it is heated to 80 C.

Unless otherwise indicated percentages are in weight percent.

What is claimed is:

l. A crosslinked plastic which is the reaction product of a mixtureconsisting essentially of a polyamide and an epoxy compound containingat least two epoxy groups per molecule, hardenable at normal temperaturein the absence of an epoxy hardener, the polyamide including residues ofl-amino-3- aminomethyl-3,5,5,-trimethylcyclohexane, said residues beingabout 20-100 percent of the diamine residues of the polyamide, saidpolyamide being about 10-99 percent of the polyamide plus epoxycompound.

2. Plastic according to claim 1, the polyamide having an averagemolecular weight of less than 3,000, and at least percent of theterminal groups of the polyamide being amino groups.

3. Plastic according to claim 1, the polyamide containing diol residues,the diol residues being up to 15 percent of the diamine residues of thepolyamide.

4. Plastic according to claim 2, the polyamide containing diol residues,the diol residues being up to 15 percent of the diamine residues of thepolyamide.

5. PLastic according to claim 1, the epoxy compound being an epoxyresin.

6. Shaped article of plastic according to claim 1.

7. Plastic according to claim 1, the moleculer weight of the polyamidebeing 1,500-10,000, and at least 70 percent of the terminal groups ofthe polyamide being amino groups.

8. Plastic according to claim 1, the molecular weight of the polyamidebeing l,500-10,000.

9. Plastic according to claim 7, the polyamide being a polyamide of adicarboxylic acid.

i k l mum) s'mrrs PATENT 0mm; QER'ELEFWA'EE11 GTE EUREH'EC'HUN PatentNo. 3 9 7 Dated Jufi 27, 1969 It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

C01. 4, line 2, "10-99 percent" should be 10-9933 percent"o Signed andsealed this 5th day of December 1972.

(SEAL) Attest:

EDWARED MQFLETQHER J1?e ROBERT GO'I'TSCHALK Attestlng OfficerCommissioner of Patents

2. Plastic according to claim 1, the polyamide having an averagemolecular weight of less than 3,000, and at least 70 percent of theterminal groups of the polyamide being amino groups.
 3. Plasticaccording to claim 1, the polyamide containing diol residues, the diolresidues being up to 15 percent of the diamine residues of thepolyamide.
 4. Plastic according to claim 2, the polyamide containingdiol residues, the diol residues being up to 15 percent of the diamineresidues of the polyamide.
 5. PLastic according to claim 1, the epoxycompound being an epoxy resin.
 6. Shaped article of plastic according toclaim
 1. 7. Plastic according to claim 1, the moleculer weight of thepolyamide being 1,500-10,000, and at least 70 percent of the terminalgroups of the polyamide being amino groups.
 8. Plastic according toclaim 1, the molecular weight of the polyamide being 1,500-10,000. 9.Plastic according to claim 7, the polyamide being a polyamide of adicarboxylic acid.